JP4385043B2 - Magnetic film manufacturing method and magnetic film - Google Patents

Description

  The present invention relates to a method for manufacturing a magnetic film formed by a plating method and a magnetic film, for example, for constituting a magnetic head.

  In a magnetic head, a magnetic film having a structure in which a magnetic layer made of a magnetic material such as FeCo or NiFe is stacked on an underlayer is used as a write pole, yoke, or shield. In this type of magnetic film, the underlayer is made of a noble metal such as Ru, so that the coercive force can be reduced and the magnetic permeability can be improved. For example, paragraph No. 0016 of Patent Document 1 discloses a structure in which a magnetic layer made of FeCo is laminated on a base layer made of Ru.

Further, when the magnetic layer is actually formed, it is generally formed to a thickness of, for example, 0.2 μm or more. As a method for forming the magnetic layer, a plating method in which the underlayer is immersed in a plating solution and a magnetic layer is deposited on the underlayer by applying a current is effective. In particular, a pulse plating method in which a current having a pulse waveform is applied is preferable. According to the pulse plating method, since plating is performed intermittently with a pulsed current waveform, the growth of crystal grains can be suppressed while ensuring the thickness of the magnetic layer, and a thick and dense magnetic layer can be obtained. Be expected.
JP 2005-25890 A

  In consideration of the above points, the inventors tried to deposit a magnetic layer by applying a pulse plating method to an underlayer made of a noble metal, but there was a problem that bubbles were taken into the magnetic layer and pinholes were generated. In addition, problems such as corrosion due to potential difference occurred.

  The present invention has been made in view of the above problems, and provides a magnetic film manufacturing method and a magnetic film capable of suppressing the generation of pinholes by pulse plating while improving the soft magnetic characteristics. Objective.

  In order to solve the above-described problems, the present invention provides a method for producing a magnetic film in which a base layer containing a noble metal element and a base metal element is subjected to pulse plating, and a plating layer made of a magnetic material is deposited on the base layer. provide.

  The inventors have studied the generation of pinholes by pulse plating, and the mechanism has been presumed as follows although it is not necessarily clear.

  That is, in the pulse plating, the first period for growing the plating layer and the second period for stopping the growth of the plating layer or etching the plating layer are alternately repeated in units of extremely short time. If the standard electrode potential of the base layer is high because the base layer is composed of only a noble metal, the high standard electrode potential of the base layer itself is added to the voltage applied to the base layer in the second period. Therefore, the potential of the base layer becomes a positive value higher than the original value. For this reason, the plating solution around the base layer is decomposed to generate bubbles such as oxygen gas. Then, when the plating layer is grown in the first period thereafter, bubbles are taken into the plating layer and pinholes are generated.

  In general, since the magnetic layer is a metal having a base potential, it is known that corrosion due to the battery effect occurs due to a potential difference from the noble metal.

  Therefore, in the present invention, an underlayer containing a noble metal element and a base metal element is employed. Such an underlayer has a lower standard electrode potential than an underlayer made of only a noble metal element. Therefore, even if pulse plating is performed, pinhole generation and corrosion of the plating layer can be suppressed.

  Further, since the above-described underlayer contains a noble metal element, excellent soft magnetic properties can be imparted to the plating layer formed on the underlayer and made of a magnetic material.

  Furthermore, the present invention provides a magnetic film comprising an underlayer containing a noble metal element and a base metal element, and a plating layer formed on the underlayer and made of a magnetic material.

  In the magnetic film according to the present invention described above, since the underlayer contains a noble metal element and a base metal element, the standard electrode potential is low. Therefore, since the plating layer is formed on the base layer, the occurrence of pinholes in the plating layer can be suppressed even if pulse plating is performed to deposit the plating layer.

  Moreover, since the underlayer contains a noble metal element, the soft magnetic properties of the plating layer made of a magnetic material can be improved.

  The present invention further discloses a thin film magnetic head using the magnetic film described above.

  As described above, according to the present invention, it is possible to provide a magnetic film manufacturing method and a magnetic film that can suppress the generation of pinholes due to pulse plating while improving the soft magnetic characteristics.

FIG. 1 is a cross-sectional view showing an embodiment of a magnetic film according to the present invention. The illustrated magnetic film 5 includes an underlayer 2 and a plating layer 3 and is formed on the substrate 1. The substrate 1 is made of a ceramic material such as Altic (Al ₂ O ₃ .TiC).

  The underlayer 2 is formed on the upper surface of the substrate 1 with a thickness Z2 of, for example, about 20 nm to 100 nm. The underlayer 2 is made of an alloy material containing a noble metal and a base metal. As the noble metal for constituting the alloy material, one or more elements selected from the group consisting of Cu, Ru, Rh, Pd, Ag, Re, Ir, Pt and Au can be adopted. Further, as the base metal, a nonmagnetic base metal is preferably used, and for example, one or a plurality of elements selected from the group consisting of Ti, V, Cr, Zr, Nb, and Mo can be employed. Although the combination of a noble metal and a base metal is arbitrary, the combination of Ru and Cr can be mentioned as an example. The amount of the base metal added to the noble metal is preferably in the range of 5 at% to 50 at%, more preferably in the range of 5 at% to 20 at%.

  The standard electrode potential of the underlayer 2 is preferably in the range of −1.00V to 0.70V. The standard electrode potential of the underlayer 2 can be adjusted by changing the types of noble metal elements and base metal elements constituting the alloy material or changing the amount of base metal added to the noble metal.

  The plating layer 3 is formed on the upper surface of the foundation layer 2. Specifically, the plating layer 3 is directly attached to the upper surface of the base layer 2, and the thickness Z3 is, for example, about 0.3 μm to 3.0 μm. The plating layer 3 is made of a magnetic material. As the magnetic material, FeCo, NiFe, or the like can be employed. The plating layer 3 can be distinguished from a layer formed by another method, for example, a layer formed by vacuum deposition or sputtering, in that it contains impurities such as sulfur and boron in the plating solution. it can.

  As another embodiment, a second plating layer made of a magnetic material may be formed on the plating layer 3. For example, when FeCo is adopted as the magnetic material of the plating layer 3, NiFe can be adopted as the magnetic material of the second plating layer.

  The magnetic film 5 described above can be used as a write pole, a yoke or a shield of a magnetic head through a necessary process such as etching.

Next, a method for manufacturing such a magnetic film 5 will be described with reference to FIGS.
First, as shown in FIG. 2, the base layer 2 is formed on the upper surface of the substrate 1. As described above, the underlayer 2 is made of an alloy material containing a noble metal and a base metal. Such an underlayer 2 can be formed by vacuum deposition, sputtering, plating, or the like.

  Next, plating is performed to form a plating layer on the upper surface of the base layer 2. The plating process is shown in FIG. Referring to FIG. 3, a plating solution 42 is placed in the plating tank 41. The component of the plating solution 42 is determined according to the composition of the plating layer to be formed. For example, when it is desired to form a CoFe plating layer, the plating solution 42 is prepared to contain Co ions and Fe ions. Cobalt sulfate and cobalt chloride are used as the Co ion supply source, and iron sulfate and iron chloride are used as the Fe ion supply source. The electrode plate 43 is connected to a power source 44.

  Then, the substrate 1 on which the underlayer 2 is formed is immersed in a plating solution 42, and the underlayer 2 is subjected to pulse plating. As a specific method of pulse plating, the electrode plate 43 is connected to the positive electrode of the power source 44 and the base layer 2 is connected to the negative electrode of the power source 44 in a state where the base layer 2 is immersed in the plating solution. A voltage V1 having the following waveform is applied.

An example of the waveform of the voltage V1 is shown in FIG. However, in FIG. 4, the horizontal axis represents time and the vertical axis represents voltage. 3 and 4, first, a constant positive voltage Va is applied to the electrode plate 43 in the first period T1. When viewed from the underlayer 2, a constant negative voltage is applied, so that the plating layer 3 can be grown on the underlayer 2. The length of the first period T1 is set to about 5 ms to 1000 ms, for example. The value of the plating current when applying a positive voltage Va, depending on the composition to be formed plating layer is set to be, for example, 0.01A ^/ cm ² ~0.1A ^/ cm 2 approximately.

Next, in the second period T2, a constant negative voltage Vb is applied to the electrode plate. Since the applied voltage becomes negative when viewed from the underlayer 2, the plating layer 3 is etched. The magnitude of the negative voltage Vb is smaller than the magnitude of the positive voltage Va. The ratio T2 / T1 of the length of the second period T2 to the length of the first period T1 is set to about 1 to 200, for example. Further, the value of the plating current when the negative voltage Vb is applied depends on the value of the plating current when the positive voltage Va is applied, but is set to, for example, about 0 to 0.03 A / cm ² .

  Then, in order to suppress the growth of crystal grains while ensuring the thickness of the plating layer 3, the first and second periods T1 and T2 are alternately repeated during the predetermined time T0.

  In the waveform shown in FIG. 4, let us consider a case where the standard electrode potential of the underlayer 2 is high because the underlayer 2 is composed of only a noble metal. In this case, since the high standard electrode potential of the base layer itself is added to the positive voltage applied to the base layer 2 in the second period T2, the potential of the base layer 2 is higher than the original positive potential. Value. For this reason, the plating solution 42 around the underlayer 2 is decomposed to generate bubbles such as oxygen gas. Then, when the plating layer 3 is grown in the first period T1 thereafter, there is a problem that bubbles are taken into the plating layer 3 to generate pinholes.

  Another example of the waveform of the voltage V1 is shown in FIG. First, the point that a constant positive voltage Va is applied to the electrode plate 43 in the first period T1 is the same as the waveform shown in FIG.

  Next, the applied voltage to the electrode plate 43 is set to zero in the second period T2. When viewed from the underlayer 2, the applied voltage becomes zero, and the growth of the plating layer 3 is stopped. The first and second periods T1 and T2 are alternately repeated in the same manner as the waveform shown in FIG.

  Even in the waveform shown in FIG. 5, there is a problem that pinholes are generated in the plating layer 3. That is, when the standard electrode potential of the foundation layer 2 is high, even if the voltage applied to the foundation layer 2 is zero in the second period T2, the high standard electrode potential of the foundation layer itself is added. For this reason, the electric potential of the base layer 2 becomes a positive value higher than the original value, and a pinhole is generated in the plating layer 3.

  FIG. 6 is a cross-sectional photograph showing the state of the plating layer when pulse plating is applied to the underlayer composed only of the noble metal. As shown in FIG. 6, it can be seen that a pinhole 63 is generated in the plating layer 62 deposited on the base layer 61, and the plating layer 62 is not grown above the pinhole 63. The line 64 is a line generated because the pinhole 63 has an influence on the FIB processing (focused ion beam processing), and is not a pinhole or corrosion.

  Referring to FIG. 3 again, the inventors employed the underlayer 2 made of an alloy material containing a noble metal and a base metal as a means for suppressing the generation of pinholes due to pulse plating. Such a base layer 2 has a lower standard electrode potential than a base layer made of only a noble metal. Therefore, even if pulse plating is applied to the underlayer 2, the generation of pinholes in the plating layer 3 can be suppressed, so that the plating layer 3 can be formed thick and dense.

  Moreover, since the underlayer 2 contains a noble metal, the soft magnetic characteristics of the plating layer 3 made of a magnetic material can be improved.

  Furthermore, as a result of investigation by the inventors, when the standard electrode potential of the underlayer 2 is high, another problem of corrosion also occurs. That is, when the standard electrode potential of the base layer 2 is high, the difference between the standard electrode potential of the base layer 2 and the standard electrode potential of the plating layer 3 increases. For this reason, if the foundation layer 2 and the plating layer 3 are exposed to a plating solution or an etching solution at a later stage of the process shown in FIG. 3, corrosion due to the battery effect occurs between the foundation layer 2 and the plating layer 3. There is a problem that occurs.

  FIG. 7 is a cross-sectional photograph showing the state of the underlayer and the plating layer after applying pulse plating to the underlayer composed only of the noble metal. As shown in FIG. 7, after pulse plating, corrosion 73 occurs between the base layer 71 and the plating layer 72.

  Regarding the corrosion problem, in the present invention, as described with reference to FIG. 3, the standard electrode potential of the underlayer 2 can be lowered, so that the standard electrode potential of the underlayer 2 and the standard electrode of the plating layer 3 are reduced. The difference from the potential can be reduced. Therefore, corrosion due to the battery effect can be avoided.

  As another embodiment, after depositing a plating layer 3 on the underlayer 2 (FIG. 3), the plating layer 3 is plated, and a second plating layer made of a magnetic material is formed on the plating layer 3. May be deposited. As plating for depositing the second plating layer, in addition to the pulse plating method described above, a normal plating method in which a constant voltage or current is applied may be employed.

  Hereinafter, the points for preventing the occurrence of pinholes and corrosion and for improving the soft magnetic characteristics will be described with reference to experimental data.

<Experiment 1>
First, an underlayer was formed on a substrate made of Altic by sputtering. As the composition of the underlayer, a composition in which Cr was added based on Rh was used. The amount of Cr added was 0 at% to 100 at% with respect to Rh. The layer thickness of the underlayer was 20 nm.

  Next, pulse plating was applied to the underlayer, and a plating layer was formed directly on the underlayer. As the composition of the plating layer, Fe75Co25 was used, and the thickness of the plating layer was 1.0 μm. As a result, a magnetic film having a structure in which an underlayer and a plating layer were laminated was obtained.

  Next, the soft magnetic characteristics of the obtained magnetic film were examined. Specifically, the easy axial direction coercive force Hc (Oe) and the magnetic permeability u ′ at 10 MHz were examined.

  Furthermore, the crystal structure of the underlayer and the impurity amount (wt%) of the plating layer were also examined. About the amount of impurities in the plating layer, the amount of elements in the plating film is determined by glow discharge mass spectrometry (GD-MS), and the total amount of elements (chlorine, sulfur and oxygen) regarded as impurities is obtained. The amount of impurities in the plating layer was used.

  Furthermore, the presence or absence of pinholes or corrosion was also examined. The experimental results are shown in Table 1 below.

  Regarding the item “Crystal structure of the underlayer” included in Table 1, hcp is a hexagonal close-packed structure, bcc is a body-centered cubic structure, and hcp-bcc is a mixture of a hexagonal close-packed structure and a body-centered cubic structure. To express.

  First, the occurrence of pinholes and corrosion will be examined. The occurrence of pinholes and corrosion is affected not only by the standard electrode potential of the underlying layer but also by the amount of impurities taken into the plating layer. That is, the plating solution contains gases such as chlorine, sulfur and oxygen. When pulse plating is applied to the underlayer with a small amount of Cr added, gas generation increases and a large amount of impurities are taken into the plating layer. Impurities in the plating layer cause pinholes and corrosion.

  When the amount of Cr added was less than 5 at%, the standard electrode potential of the underlayer increased and the amount of impurities in the plating layer increased. For this reason, either pinholes or corrosion occurred (Samples 1 and 2).

  On the other hand, when the Cr addition amount was 5 at% or more, the standard electrode potential of the underlayer was lowered and the impurity amount of the plating layer was reduced. Therefore, both pinholes and corrosion could be suppressed (Samples 3 to 15).

  Therefore, it can be seen that the Cr addition amount should be 5 at% or more from the viewpoint of preventing pinholes or corrosion.

  Next, soft magnetic properties such as easy axial coercivity and magnetic permeability will be examined. When the Cr addition amount was 50 at% or less, the crystal structure of the underlayer was dominated by the hexagonal close-packed structure (hcp), which is the crystal structure of the noble metal Rh. For this reason, it was possible to secure excellent soft magnetic characteristics such as an easy axial coercivity of 40 (Oe) or less and a magnetic permeability of 600 or more (Samples 1 to 11).

  On the other hand, when the Cr addition amount is larger than 50 at%, the body-centered cubic structure (bcc), which is the crystal structure of the base metal Cr, is dominant in the crystal structure of the underlayer. For this reason, the soft magnetic characteristics were deteriorated such that the easy axial coercive force exceeded 40 (Oe) and the magnetic permeability was less than 600 (samples 12 to 15).

  Therefore, from the viewpoint of securing excellent soft magnetic properties, it is understood that the Cr addition amount should be 50 at% or less.

  From the above results, in order to prevent pinholes or corrosion and at the same time ensure excellent soft magnetic properties, the Cr addition amount may be 5 at% or more and 50 at% or less. More preferably, in order to further improve the soft magnetic characteristics, the Cr addition amount is set to 5 at% or more and 20 at% or less.

<Experiment 2>
In Experiment 2, the description of the same points as in Experiment 1 may be omitted below. In Experiment 2, a composition in which Ti was added based on Pd was used as the composition of the underlayer. The amount of Ti added was 0 at% to 100 at% with respect to Pd. Further, as the composition of the plating layer, Fe75Co25 was used as in Experiment 1 above.

  The experimental results are shown in Table 2 below. However, in Experiment 2, the amount of impurities (wt%) in the plating layer was not examined.

  Regarding the item “Crystal structure of the underlayer” in Table 2, fcc indicates a face-centered cubic structure, hcp indicates a hexagonal close-packed structure, and fcc-hcp indicates that a face-centered cubic structure and a hexagonal close-packed structure are mixed.

  First, the occurrence of pinholes and corrosion will be examined. When the amount of Ti added was less than 5 at%, either pinholes or corrosion occurred. This is presumably because the standard electrode potential of the underlayer increased and the amount of impurities in the plating layer increased (samples 16 and 17).

  On the other hand, when the Ti addition amount was 5 at% or more, both pinholes and corrosion could be suppressed. This is presumably because the standard electrode potential of the underlying layer was lowered and the amount of impurities in the plating layer was reduced (Samples 18 to 30).

  Therefore, it can be seen that the amount of Ti added should be 5 at% or more from the viewpoint of preventing pinholes or corrosion.

  Next, soft magnetic properties such as easy axial coercivity and magnetic permeability will be examined. When the Ti addition amount was 50 at% or less, the crystal structure of the underlayer was dominated by the face-centered cubic structure that is the crystal structure of the noble metal Pd. For this reason, it was possible to ensure excellent soft magnetic properties such as an easy axial coercive force of 40 (Oe) or less and a magnetic permeability of 600 or more (Samples 16 to 26).

  On the other hand, when the Ti addition amount was larger than 50 at%, the crystal structure of the underlayer was dominated by the hexagonal close-packed structure that is the crystal structure of the base metal Ti. For this reason, the soft magnetic characteristics were deteriorated such that the easy axial coercive force exceeded 40 (Oe) and the magnetic permeability was less than 600 (samples 27 to 30).

  Therefore, from the viewpoint of securing excellent soft magnetic properties, it can be seen that the Ti addition amount should be 50 at% or less.

  From the above results, in order to prevent pinholes or corrosion and at the same time ensure excellent soft magnetic properties, the amount of Ti added may be 5 at% or more and 50 at% or less. More preferably, in order to further improve the soft magnetic characteristics, the amount of Ti added is set to 5 at% or more and 20 at% or less.

<Experiment 3>
In Experiment 3, the description of points that overlap with the previous Experiment 2 may be omitted. In Experiment 3, as the composition of the underlayer, a composition in which Cr was added based on Ru was used. The amount of Cr added was 0 at% to 100 at% with respect to Ru. Further, as the composition of the plating layer, Fe75Co25 was used as in Experiment 2 above. The experimental results are shown in Table 3 below.

  Regarding the item “Crystal structure of the underlayer” in Table 3, hcp indicates a hexagonal close-packed structure, bcc indicates a body-centered cubic structure, and hcp-bcc indicates that a hexagonal close-packed structure and a body-centered cubic structure are mixed. Is the same as in Table 1.

  First, the occurrence of pinholes and corrosion will be examined. When the amount of Cr added was less than 5 at%, either pinholes or corrosion occurred. This is presumably because the standard electrode potential of the underlayer increased and the amount of impurities in the plating layer increased (samples 31 and 32).

  On the other hand, when the amount of Cr added is 5 at% or more, both pinholes and corrosion could be suppressed. This is presumably because the standard electrode potential of the underlying layer was lowered and the amount of impurities in the plating layer was reduced (Samples 33 to 41).

  Therefore, it can be seen that the Cr addition amount should be 5 at% or more from the viewpoint of preventing pinholes or corrosion.

  Next, soft magnetic properties such as easy axial coercivity and magnetic permeability will be examined. When the Cr addition amount is 55 at% or less, the crystal structure of the underlayer is dominated by the hexagonal close-packed structure (hcp), which is the crystal structure of the noble metal Ru. Therefore, considering the margin of the Cr addition amount, if the Cr addition amount is 50 at% or less, excellent soft magnetic characteristics such as easy axial coercive force of 40 (Oe) or less and permeability of 600 or more are obtained. (Samples 31 to 38) can be secured.

  On the other hand, when the Cr addition amount is larger than 50 at%, the body-centered cubic structure (bcc), which is the crystal structure of the base metal Cr, is dominant in the crystal structure of the underlayer. For this reason, the soft magnetic characteristics were deteriorated such that the easy axial coercive force exceeded 40 (Oe) and the magnetic permeability was less than 600 (samples 39 to 41).

  Therefore, from the viewpoint of securing excellent soft magnetic properties, it is understood that the Cr addition amount should be 50 at% or less.

  From the above results, in order to prevent pinholes or corrosion and at the same time ensure excellent soft magnetic properties, the Cr addition amount may be 5 at% or more and 50 at% or less. More preferably, in order to further improve the soft magnetic characteristics, the Cr addition amount is set to 5 at% or more and 20 at% or less.

<Experiment 4>
In Experiment 4, the description of points overlapping with the previous Experiment 2 may be omitted. In Experiment 4, a composition in which Cr was added based on Pt was used as the composition of the underlayer. The amount of Cr added was 0 at% to 100 at% with respect to Pt. Further, as the composition of the plating layer, Fe75Co25 was used as in Experiment 2 above. The experimental results are shown in Table 4 below.

  Regarding the item “Crystal structure of the underlayer” in Table 4, fcc indicates a face-centered cubic structure, bcc indicates a body-centered cubic structure, and fcc-bcc indicates that a face-centered cubic structure and a body-centered cubic structure are mixed.

  First, the occurrence of pinholes and corrosion will be examined. When the amount of Cr added was less than 5 at%, either pinholes or corrosion occurred. This is presumably because the standard electrode potential of the underlayer increased and the amount of impurities in the plating layer increased (samples 42 and 43).

  On the other hand, when the amount of Cr added is 5 at% or more, both pinholes and corrosion could be suppressed. This is presumably because the standard electrode potential of the underlying layer was lowered and the amount of impurities in the plating layer was reduced (samples 44 to 52).

  Therefore, it can be seen that the Cr addition amount should be 5 at% or more from the viewpoint of preventing pinholes or corrosion.

  Next, soft magnetic properties such as easy axial coercivity and magnetic permeability will be examined. When the Cr addition amount is 55 at% or less, the crystal structure of the underlayer is dominated by the hexagonal close-packed structure (hcp), which is the crystal structure of the noble metal Ru. Therefore, considering the margin of the Cr addition amount, if the Cr addition amount is 50 at% or less, excellent soft magnetic characteristics such as easy axial coercive force of 40 (Oe) or less and permeability of 600 or more are obtained. (Samples 31 to 38) can be secured.

  Therefore, from the viewpoint of securing excellent soft magnetic properties, it is understood that the Cr addition amount should be 50 at% or less.

  From the above results, in order to prevent pinholes or corrosion and at the same time ensure excellent soft magnetic properties, the Cr addition amount may be 5 at% or more and 50 at% or less. More preferably, in order to further improve the soft magnetic characteristics, the Cr addition amount is set to 5 at% or more and 20 at% or less.

<Experiment 5>
In Experiment 5, the same points as in Experiment 2 above may not be described below. In Experiment 5, a composition in which Ti was added based on Pt was used as the composition of the underlayer. The amount of Ti added was 0 at% to 100 at% with respect to Pt. Further, as the composition of the plating layer, Fe75Co25 was used as in Experiment 2 above. The experimental results are shown in Table 5 below.

  Regarding the item “Crystal structure of the underlayer” in Table 5, hcp is a hexagonal close-packed structure, fcc is a face-centered cubic structure, bcc is a body-centered cubic structure, and fcc-bcc is a mixture of face-centered cubic structure and body-centered cubic structure. Represents that you are doing.

  First, the occurrence of pinholes and corrosion will be examined. When the amount of Ti added was less than 5 at%, either pinholes or corrosion occurred. This is presumably because the standard electrode potential of the underlayer increased and the amount of impurities in the plating layer increased (samples 53 and 54).

  On the other hand, when the Ti addition amount was 5 at% or more, both pinholes and corrosion could be suppressed. This is presumably because the standard electrode potential of the underlying layer was lowered and the amount of impurities in the plating layer was reduced (Samples 55 to 63).

  Therefore, it can be seen that the amount of Ti added should be 5 at% or more from the viewpoint of preventing pinholes or corrosion.

  Next, soft magnetic properties such as easy axial coercivity and magnetic permeability will be examined. When the Ti addition amount was 50 at% or less, excellent soft magnetic properties such as easy axial coercivity of 40 (Oe) or less and permeability of 600 or more could be secured (Samples 53 to 60).

  On the other hand, when the Ti addition amount is larger than 50 at%, the soft magnetic characteristics are deteriorated such that the easy axial coercive force exceeds 40 (Oe) and the magnetic permeability is less than 600 (Samples 61 to 61). 63).

  Therefore, from the viewpoint of securing excellent soft magnetic properties, it is understood that the Cr addition amount should be 50 at% or less.

  From the above results, in order to prevent pinholes or corrosion and at the same time ensure excellent soft magnetic properties, the amount of Ti added may be 5 at% or more and 50 at% or less. More preferably, in order to further improve the soft magnetic characteristics, the amount of Ti added is set to 5 at% or more and 20 at% or less.

<Experiment 6>
In the experiment 6, the description overlapping with the previous experiment 2 may be omitted below. In Experiment 6, a composition in which Ti was added based on Ru was used as the composition of the underlayer. The amount of Ti added was 0 at% to 100 at% with respect to Ru. Further, as the composition of the plating layer, Fe75Co25 was used as in Experiment 2 above. The experimental results are shown in Table 6 below.

First, the occurrence of pinholes and corrosion will be examined. When the amount of Ti added was less than 5 at%, either pinholes or corrosion occurred. This is presumably because the standard electrode potential of the underlayer increased and the amount of impurities in the plating layer increased (samples 64 and 65).

  On the other hand, when the Ti addition amount was 5 at% or more, both pinholes and corrosion could be suppressed. This is presumably because the standard electrode potential of the underlying layer was lowered and the amount of impurities in the plating layer was reduced (Samples 66 to 74).

  Therefore, it can be seen that the amount of Ti added should be 5 at% or more from the viewpoint of preventing pinholes or corrosion.

  Next, soft magnetic properties such as easy axial coercivity and magnetic permeability will be examined. When the Ti addition amount was 50 at% or less, excellent soft magnetic characteristics such as an easy axial coercive force of 40 (Oe) or less and a magnetic permeability of 600 or more could be secured (Samples 64-71).

  On the other hand, when the Ti addition amount is larger than 50 at%, soft magnetic characteristics are deteriorated such that the easy axial coercive force exceeds 40 (Oe) and the magnetic permeability becomes less than 600 (samples 72 to 72). 74).

  Therefore, from the viewpoint of securing excellent soft magnetic properties, it is understood that the Cr addition amount should be 50 at% or less.

  From the above results, in order to prevent pinholes or corrosion and at the same time ensure excellent soft magnetic properties, the amount of Ti added may be 5 at% or more and 50 at% or less. More preferably, in order to further improve the soft magnetic characteristics, the amount of Ti added is set to 5 at% or more and 20 at% or less.

  8 is a plan view of the medium facing surface side showing an embodiment of a thin film magnetic head according to the present invention, FIG. 9 is a front sectional view of the thin film magnetic head shown in FIG. 8, and FIG. 10 is shown in FIGS. 2 is an enlarged cross-sectional view of an element portion of a thin film magnetic head. In any of the drawings, dimensions, proportions, etc. are exaggerated or omitted for convenience of illustration.

First, referring to FIGS. 8 and 9, the slider base 100 is made of a ceramic material such as AlTiC (Al ₂ O ₃ —TiC), for example, and has a geometric shape for controlling the flying characteristics on the medium facing surface. is doing. As a representative example of such a geometric shape, in the embodiment, a first step portion 11, a second step portion 12, a third step portion 13, and a fourth step are formed on the base surface 10 of the slider base 100. The example provided with the part 14 and the 5th step part 15 is shown. The basal plane 10 becomes a negative pressure generating portion with respect to the air flow direction indicated by the arrow A, and the second step portion 12 and the third step portion 13 constitute a stepped air bearing rising from the first step portion 11. To do. The surfaces of the second step portion 12 and the third step portion 13 are ABS.

  The fourth step portion 14 rises in a step shape from the base surface 10, and the fifth step portion 15 rises in a step shape from the fourth step portion 14. The writing element 200 and the reading element 300 are provided in the fifth step portion 15.

  Next, referring to FIG. 10, the reading element 300 includes an MR element 30, a lower shield film 31, and an upper shield film 33. In the illustrated embodiment, the MR element 30 is a CIP type GMR element. The MR element 30 that is a CIP type GMR element generates an insulating gap between the lower surface of the MR element and the lower shield film 31 and generates an insulating gap between the upper surface of the MR element and the upper shield film 33. The insulating gap film 32 is disposed inside.

  Unlike the illustrated embodiment, the MR element 30 may be a CPP type TMR element or GMR element. The MR element 30 formed of a CPP type TMR element or GMR element is not insulated between the lower surface of the MR element and the lower shield film 31 and is insulated between the upper surface of the MR element and the upper shield film 33. It arrange | positions in the aspect which does not pass through a gap.

  The write element 200 includes a lower magnetic film 21, an upper magnetic film 22, thin film coils 231 and 232, and a write gap film 24. The lower magnetic film 21 has a lower yoke part 210 and a lower pole part 211. The lower pole portion 211 is provided so as to protrude from the end of the lower yoke portion 210 on the side facing the recording medium, that is, on the ABS 12 and 13 side. The lower pole portion 211 is provided on the insulating film 34 adjacent to the upper shield film 33 via a base film 215. Reference numeral 213 is a recess provided in the lower yoke part 210, and reference numeral 270 is an insulating film provided so as to fill the recess 213.

  The upper magnetic film 22 has an upper yoke portion 221 and upper pole portions (222, 223). The distinction between the yoke part and the pole part is not necessarily clear on the magnetic circuit, but can be distinguished by the size of the area. That is, a portion having a large area is referred to as a yoke portion, and a portion having a small area as a result of being narrowed down from the large area portion is referred to as a pole portion. The upper magnetic film 22 is covered with an insulating film 274 such as alumina.

  The upper yoke portion 221 is magnetically coupled to the lower yoke portion 210 by a rear coupling portion 26 that is spaced from the lower yoke portion 210 and is located rearward when viewed from the ABSs 12 and 13 facing the recording medium. . The thin film coils 231 and 232 are electrically insulated by insulating films 25, 271, 272, 275 and 276 existing between the lower yoke part 210 and the upper yoke part 221. The insulating films 25, 271, 272, 275, and 276 are formed of an organic insulating film, an inorganic insulating film, or a combination thereof.

  The upper pole portion (222, 223) includes an upper pole end portion 223 and an upper pole rear portion 222, and faces the lower pole portion 211 with the base film 225 and the write gap film 24 interposed therebetween.

  In the above-described thin film magnetic head, the configuration shown in the magnetic film 5 of FIG. 1 can be adopted for the lower pole portion 211 or the upper pole end portion 223 of the write element 200. For example, the lower pole portion 211 and the base film 215 correspond to the plating layer 3 and the base layer 2 of the magnetic film 5 shown in FIG. Further, the upper pole end portion 223 and the base film 225 are configured to correspond to the plating layer 3 and the base layer 2 of the magnetic film 5 shown in FIG. Thus, by adopting the configuration shown in the magnetic film 5 of FIG. 1 as the lower pole portion 211 or the upper pole end portion 223 of the write element 200, the performance of the write element can be improved.

  Further, the lower shield film 31 or the upper shield film 33 of the reading element 300 can adopt the configuration shown in the magnetic film 5 of FIG. For example, the lower shield film 31 and the underlying film 310 have a configuration corresponding to the plating layer 3 and the underlying layer 2 of the magnetic film 5 shown in FIG. Further, the upper shield film 33 and the base film 330 thereof correspond to the plating layer 3 and the base layer 2 of the magnetic film 5 shown in FIG. As described above, by adopting the configuration shown in the magnetic film 5 of FIG. 1 as the lower shield film 31 or the upper shield film 33 of the reading element 300 and increasing the magnetic permeability, the performance of the reading element can be improved. it can.

  The illustrated thin film magnetic head is a thin film magnetic head for in-plane magnetic recording. However, the present invention is not limited to this, and the thin film magnetic head for perpendicular magnetic recording can employ the magnetic film 5 shown in FIG. it can.

  While the present invention has been described with reference to the embodiment, it is needless to say that the present invention is not limited to this embodiment, and various modifications and changes can be made within the scope of the claims.

It is sectional drawing which shows one Embodiment of the magnetic film which concerns on this invention. It is a figure explaining one Embodiment of the manufacturing method of the magnetic film which concerns on this invention. It is a figure which shows the process after the process shown in FIG. It is a figure which shows the example of the voltage waveform in pulse plating. It is a figure which shows another example of the voltage waveform in pulse plating. It is a cross-sectional photograph which shows the state of the plating layer at the time of applying pulse plating to the base layer comprised only from the noble metal. It is a cross-sectional photograph which shows the state of a base layer and a plating layer after applying pulse plating to the base layer comprised only from the noble metal. 1 is a plan view of a medium facing surface side showing an embodiment of a thin film magnetic head according to the present invention. FIG. FIG. 9 is a front sectional view of the thin film magnetic head shown in FIG. 8. FIG. 10 is an enlarged cross-sectional view of an element portion of the thin film magnetic head shown in FIGS. 8 and 9.

Explanation of symbols

1 Substrate 2 Underlayer 3 Plating layer

Claims (7)

A method for producing a magnetic film, comprising subjecting an underlayer to pulse plating and depositing a plating layer made of a magnetic material on the underlayer,
The underlayer is made of an alloy material containing a noble metal element and a base metal element,
The combination of the noble metal element and the base metal element is (Rh, Cr), (Ru, Cr), (Pt, Cr), (Pd, Ti), (Pt, Ti) or (Ru, Ti). Yes,
The amount of the base metal element added to the noble metal element is in the range of 5 at% to 50 at%.
Manufacturing method of magnetic film. 2. The method of manufacturing a magnetic film according to claim 1, wherein the standard electrode potential of the underlayer is in a range of −1.00 V to 0.70 V. 3 . A method of manufacturing a magnetic film according to claim 1 or 2 ,
After the plating layer made of a magnetic material is deposited on the underlayer, the plating layer is plated to deposit a second plating layer made of a magnetic material on the plating layer.
Manufacturing method of magnetic film. A magnetic film comprising an underlayer and a plating layer formed on the underlayer and made of a magnetic material,
The underlayer is made of an alloy material containing a noble metal element and a base metal element,
The combination of the noble metal element and the base metal element is (Rh, Cr), (Ru, Cr), (Pt, Cr), (Pd, Ti), (Pt, Ti) or (Ru, Ti). Yes,
The amount of the base metal element added to the noble metal element is in the range of 5 at% to 50 at%.
Magnetic film.   5. The magnetic film according to claim 4, wherein a standard electrode potential of the underlayer is in a range of −1.00V to 0.70V.   6. The magnetic film according to claim 4, comprising a second plating layer formed on the plating layer and made of a magnetic material. A thin film magnetic head including a writing element, a reading element, and a slider,
The write element or the read element includes a magnetic film according to any one of claims 4 to 6, wherein the slider supports the write element and the read element.
Thin film magnetic head.